Interventions: A Life in War and Peace, by Kofi Annan with Nader Mousavizadeh, Allen Lane, RRP£25/Penguin, RRP$36, 400 pages

Those tempted to approach Kofi Annan’s memoirs via the “Washington read” – going straight to the index and then to anecdotal mentions of the great and the good – may be briefly titillated, but they will not be distracted for long. Every so often in Interventions, his taut and timely memoir, the former UN secretary-general, so famous for his equanimity, acquiesces to the editor’s eternal desire for headlines and delivers a gentle jab at a fellow statesman. So we read this of Tony Blair in 2006 as the then British prime minister tells Annan that he is against calling on Israel to impose an immediate ceasefire in Lebanon: “Something had changed in Blair and with it, I felt, his ability to act as a credible mediator in this conflict.”

Then there is the early passage about Colin Powell, who, we read, comes to see Annan six weeks after the invasion of Iraq with a “huge smile” on his face. “Kofi, they have made an honest man of me,” the then secretary of state says. “They’ve found the mobile labs.” Poor Powell! While subsequent mentions make clear Annan retains a huge affection for him – possibly not true of Blair – this extract will have been yet another wounding blow to the general. Bill Clinton and Madeleine Albright, to mention just two others, will also not be entirely comfortable with all they read here, and deservedly so.

Yet, though such anecdotes have gathered press attention and no doubt reflect long-cloaked exasperations, this is not a conventional point-scoring memoir: not only is it free of the dreary accounts of process that clog up so many statesmen’s books; it also all but rises above the temptation to settle old scores. Only Richard Butler, the bombastic Australian weapons inspector, and John Bolton, George W Bush’s hawkish UN ambassador, face Annan’s headmasterly disapproval. (To be fair, the latter may be disappointed he does not receive more of a tongue-lashing.)

Interventions is, instead, a treatise on the doctrine that has defined and scarred the post-cold war years: interventionism. It is part reflection, part stricture and part call to arms. No one is better suited to address this, for it has also defined and scarred Annan himself, given how the wrenching sagas of Yugoslavia, Rwanda and indeed Iraq – not to forget East Timor, Kosovo and Lebanon, and now Syria – have enveloped his career.

Diplomats wrestling with “what to do” about Syria should turn to an exchange early in the book, between Annan and a journalist in Somalia. It encapsulates the conundrum facing would-be interveners. The conversation took place in 1992 as Somalia’s humanitarian crisis gathered speed, and as pressure grew to expand the numbers and ambition of the UN’s peacekeeping force. It was also, of course, shortly before the UN’s missions in Rwanda and Yugoslavia reached their awful denouements.

Annan was then deputy head of the UN’s peacekeeping department. A journalist suggests the UN should run the capital, Mogadishu. “That will take an enormous number of troops,” Annan replies. “And troops that can take the kind of risks necessary.” This divergence between the international community’s professed desire to do something and “the resources and risks it was willing to commit” lay at the heart of the peacekeeping nightmares to come, Annan reflects. As he has suggested recently, we can be sure that if Russia and China reversed course and backed intervention in Syria, we would see London, Paris and Washington finding any number of reasons not to send in troops.

This book is an attempt by Annan to define a coherent international approach to intervention and also a viable role for his beloved UN, given the constraints it faces from the Security Council. He does not absolve the UN of responsibility in the Yugoslav and Rwandan debacles. He acknowledges it is wrong to blame the failures of UN missions entirely on the lack of political will of Security Council powers. But he does rightly highlight the duplicity of the west in its relations with the UN during those years and the difficulty of running missions when some of your nominal subordinates report to an outside power.

Annan was head of UN peacekeeping during those terrible 100 days of the genocide in Rwanda in 1994. He opens his account of Rwanda scrupulously by transcribing an impassioned telegram from the UN military commander Romeo Dallaire, in January 1994 – three months before the killing began. Dallaire had been warned of impending massacres and wanted to raid a suspected arms cache. Annan’s department ordered him to stand down. It is a decision Annan has been excoriated for; last year he told this reviewer how he has often wondered what he could have done differently in those days. But emoting is not his style and does not feature in these pages. He is, after all, a formal and very private public servant steeped in the undemonstrative official ways of 1950s colonial Africa, where he came of age.

While some will cavil at the lack of a formal apology, he rightly highlights the dilemma the UN faced at the time and the sorry role of the west. The US was losing any appetite for peacekeeping in the wake of the debacle of “Black Hawk Down” in Somalia the previous year. Annan feared a clash could lead to the closing down of the UN missions in Rwanda and elsewhere. A few months later, when the massacres were at their height, he appealed for more troops. No one would send any, even though it was clear the slaughter was being carried out mainly by civilians with machetes and hoes. The same broad shaming point applies in the case of Bosnia, where France, Britain and the US played a disgraceful role in 1993 in watering down international responsibilities to protect the safe havens.

Some will say there is insufficient acknowledgement of UN ineptitude on the ground. Sceptics will argue that the ambition of making the organisation an agent of change is in any case a pipe-dream. But Annan and his co-author, Nader Mousavizadeh, a former aide, embody the UN at its idealistic and yet level-headed best. They argue cogently, for example, that sometimes its interventions are best focused on education and Aids.

The pair hope this will be the last word on intervention. Now Annan’s editors should urge a more personal memoir. If he includes his after-dinner jokes about Soviet leaders, memories of Haile Selassie, and more lunches such as the one he recalls here when hosting Dominique de Villepin, Joschka Fischer and Powell, it will be the perfect complement to this serious and salutary account.

Alec Russell is the FT’s news editor and a former Johannesburg bureau chief. He is author of ‘After Mandela: The Battle for the Soul of South Africa’ (Windmill Books)